Obstructive sleep apnea syndrome is associated with metabolic syndrome and inflammation

Obstructive sleep apnea (OSA) is an independent risk factor for cardiovascular morbidity and mortality. However, the underlying mechanism is unclear. In this cross-sectional study, we investigated the influence of OSA on metabolic syndrome (MetS) and inflammation, which were considered as cardiovascular risks. A total of 144 consecutive male patients who underwent standard polysomnography were enrolled. Fasting blood samples were obtained from all patients for glucose, high-sensitivity C-reactive protein (hs-CRP) and lipids measurement. A metabolic score was established as the total number of the positive diagnostic criteria of metabolic syndrome for each patient. Systolic blood pressure, diastolic blood pressure, fasting glucose, hs-CRP and metabolic score significantly increased with the aggravation of OSA severity. Metabolic score increased from 1.74 ± 1.20 to 2.89 ± 0.99 with OSA severity (p = 0.000). hs-CRP increased from 0.68 (0.43-1.10) to 1.44 (0.62-4.02) mg/L with OSA severity (p = 0.002). After adjustment for confounders, apnea-hypopnea index and body mass index (BMI) were the major contributing factors for metabolic score (β = 0.257, p = 0.003 and β = 0.344, p = 0.000, respectively), lowest O2 saturation and BMI were the independent predictors of hs-CRP (β = -0.255, p = 0.003 and β = 0.295, p = 0.001, respectively). OSA is independently associated with sum of metabolic components and hs-CRP.